Bevel-gage



(No Model.)

0. BYRNE.

BBVEL GAGE.

No. 550,904. PatentedDemfi, 1895.

qAwlligikg INVENTOR @WQM A" DREW B GRANAM. PHOTO-UTNQWASHINGFDN. 0.0.

UNITED STATES PATENT OFFICE.

CHRISTOPHER BYRNE, OF PITTSBURG, PENN SYLVANIA.

BEVEL-GAG E.

SPECIFICATION forming part of Letters Patent No. 550,904, dated December 3, 1895. Application filed May 2'7, 1895. Serial No. 550,735. (No model.)

To all whom it may concern:

Be it known that I, CHRISTOPHER BYRNE, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Bevel-Gages, of which the following is a full,clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a plan view of my improved bevel. Fig. 2 is a side elevation of the same, and Fig. 3 is a central sectional view showing the set-screw.

My invention relates to the combination squares employed by mechanics, draftsmen, or carpenters and is designed to afiord a simple device of this character which shall have a Wide range of usefulness either as a T-square or a protractor and can be employed for laying off angles where such angle is specified either by the number of degrees or by the inch or fraction of an inch to the foot.

In the drawings, in which similar numerals denote corresponding parts, 2 indicates an annular disk composed of two separated annular plates 3 and 4, each having at its base an integral projecting stem or handle portion 5, these two flat-handle plates being secured together at their ends by suitable rivets passing through them and through a spacingplate 6 between them. Secured to the upper plate 3 is a handle 7, which extends to the base of the annulus and is provided on each side with graduations, which are preferably inches and fractions thereof. Each annulus is provided with an innerly-projecting plate 8, which is in line with the handle and extends slightly beyond the center of the annulus. The handle is preferably of such length that, taken with the inwardly projecting plates, a rule of twelve inches in length is afforded and the upper plate of the inwardlyprojecting arm is graduated similarly to the handle portion for this purpose. Between the two annular plates is carried a long arm 9, which is slotted for a considerable portion of its length, this arm when in intermediate position extending in both directions beyond the circumference of the annulus or ring. Through the slot and through the inwardlyprojecting plate passes a clamping-screw 10,

having a thumb nut 11, engaging its upwardly projecting screw threaded end portion. The lower end of this screw is preferably fiush with the surface of the lower plate, so that the instrument will lie flat upon a plane surface, and the stem of the screw is reduced at its intermediate portion, so that the slot in the swinging arm may be narrow. The inner circumference of the annulus is divided into degrees, which preferably begin at zero at its upper portion in line with the handle, and thence read in both directions to one hundred and eighty degrees at the opposite side. The outer circumference of the annulus is divided into inches and fractions of inches to the foot, these graduations preferably beginning at each quarter-arc of the circumference and extending to the beginning of the next quarter-arc. The handle 7 having four straight sides, any one of these sides can be applied to a plane surface and the arm 9 adjusted so as to extend at the required angle.

The advantages of my invention will be apparent to those skilled in the art, since the handle affords a ruler, the swinging arm when placed at right angles thereto gives a T- square, and this arm may be swung and slid endwise to any point desired in laying off angles either by the degree or by the percentage of distance to the foot. Moreover, the instrument is adapted to lie flat upon a plane surface, all parts of its under face lying in the same plane.

Many variations may be made in the shape and length of the various parts, the number and character of the graduations, and in the material used for the instrument within the scope of the following claims.

I claim 1. The combination with an annulus composed of two separated annular plates, at least one of which is provided along its edge with graduations, of a swinging arm interposed between said plates; substantially as described.

2. The combination with an annulus composed of separated plates, of a handle secured thereto, the under face of the handle being in the same plane with the under'face of the annulus, and a swinging arm interposed between the plates of the annulus; substantially as described.

8. The combination with an annulus composed of separated plates, having inwardly projecting radial arms, of a swinging arm of greater length than the diameter of the annulus and pivoted between said radial arms; substantially as described.

4. The combination with an annulus composed of separated plates, each having an outwardly extending handle'portion and an inwardly extending radial arm, of a swinging.

arm interposed between the annular plates, and having a slot through which passes a setscrew in the inwardly projecting arms; substantially as described.

CHRISTOPHER BYRNE.

\Vitnesssf I r H. M. Oonwm, 1 E. GAITHER. 

